could anyone tell me if the bell housing bolt patteren is the same between the the ef-el to the ba, or is ba different, cheers phill.

I think El is the same as EA.

EA bolts up minus 2 small bolts on the bottom of the bellhousing.

im lead to believe this is the same for the AU bellhousings as well but I havent seen one in person.

I agree. I havent seen the all next to each other but EA-EL is the same, AU-BF is the same, and EA-BF are the same except for the 2 bottom support bolts (all the important ones still line up).

i have a spare EF backing plate and a BA T5z in bits, all the mayjor bolt hole line up. a few around the bottom do not, nothing a pair cutom fabed gearbox to block braces wont fix